Internal taper micrometer



Jan. 25, 1966 G. L. GERSHMAN 3,230,630

INTERNAL TAPER MIGROMETER Filed Aug. 2, 1963 INVENTOR GEORGE L. GERSHMAN ATTORNEY United States Patent 3,230,630 INTERNAL TAPER MICROMETER George L. Gershman, 100 Grove St., Worcester, Mass. Filed Aug. 2, 1963, Ser. No. 299,650 2 Claims. (Cl. 33174) This invention relates to a new and improved internal taper micrometer and reference is hereby made to my prior Patent No. 2,746,15 8 issued May 22, 1950 showing a taper micrometer for external measurement.

The principal object of the present invention relates to a new and improved internal taper micrometer by which means internal tapers may be accurately gauged and including means to vary the taper of and to relatively adjust a pair of very rigid interpivoted tapering anvils or the like by means of a micrometer device in order to accurately determine the interior diameter of a tapered hold or other like member.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which:

FIG. 1 is a view in elevation illustrating the device;

FIG. 2 is a-similar view with parts in section;

FIG. 3 is an enlarged view in elevation of the sine bar;

FIG. 4 is a view in elevation, looking in the direction of arrow 4 in FIG. 1, and

FIG. 5 shows a modification.

In carrying out the present invention there is provided a pair of rigid anvils which are elongated, tapered and ground to a conical conformation, at least in part. These anvils are indicated at and 12 and are substantially alike but reversed or complementary to each other, and they are finished in the areas at 14 and 16 to form together a frusto-conical member as shown in solid lines in FIG. 1.

These anvils pivot relative to each other as a comparison of FIGS. 1 and 2 shows, and they may be moved between the position shown in FIG. 1 for measuring a maximum taper, or they may be gradually and minutely adjusted to the position shown in FIG. 2 wherein the edge surfaces at 18 and 20 are parallel showing a zero taper reading. When in the zero taper position of FIG. 2, fiat cut away surfaces at 22 and 24 coincide and abut each other forming a stop for the zero position.

The axis of the pivoting motion resides in an oscillatable cross pin 26 forming a fixed part of the sine bar (see FIG. 3). The sine bar is provided with a base at 28 which is fixedly associated relative to the anvil 10 by being inset therein. Pin 26 is oscillatably mounted in a pair of spaced cars 30 fixedly mounted on the anvil 12 at the flat surface thereof 32 and the sine bar 34 oscillates with the pin. In other words, the pin 26 will oscillate with the sine bar 34 which as seen in FIG. 2 depends from anvil 10 from the flat surface thereof at 36. These flat surfaces of course contact in the maximum taper position shown in solid lines in FIG. 1.

The sine bar 34 is also provided with another pin 38 fixed with relation thereto, this pin being cylindrical, and appearing at the free end of the sine bar 34. Pin 38 is engaged on its surface by the free end of the measuring finger 40 of the micrometer device 44 having the thimble 42.

The micrometer device 44 is calibrated to read zero with the anvils spread apart to their greatest position as shown in FIG. 2 and this is the extreme position of departure between the two anvils, with the two surfaces 22 and 24 contacting. The measuring finger 40 can be retracted by the thimble 42 to allow the sine bar to pivot in a counterclockwise direction in FIG. 2, thus causing anvil 10 to approach anvil 12, and this will provide readings on the micrometer measuring device in thousandths 3,230,630 Patented Jan. 25, 1966 "ice of an inch as usual with such devices, leading to a maximum in the closed position of the anvils as shown in FIG. 1, with the surfaces 32 and'36 now contacting and the sine bar in an upright position rather than the relatively inclined position as shown in FIG. 2.

The adjustment and the measurement is very accurate because the free end of the finger 40 is ground fiat and the surface of the pin 38 is accurately cylindrical. The fiat end of the finger 40 always contacts the cylindrical surface of this pin. The measuring device is of course in fixed position with respect to the anvil 12 as shown in FIG. 2, and any suitable handle may be applied to either anvil as desired.

It will be seen that this invention provides a very convenient and accurate device for measuring internal tapers of any description. The instrument has a wide range of measurement and due to the construction involved the anvils themselves are extremely rigid and cannot be deflected in any way to cause a measurement to be made inaccurately. In the device illustrated, the micrometer reading is between Zero and forty-two degrees or thereabouts and it will be seen that the diameter capacity is extensive due to the conical shape of the outside surfaces of the anvils.

If it is desired to provide a wider range of measurement, one or both anvils can be separated into two parts as at 46, 48 in FIG. 5. One part as portion 48 may be provided with interengaging means such as a dovetail 50 on which part 46 can slide, and a lead screw 52 can be used to adjust part 46 to and from anvil 20. Thus the anvils can be separated for a larger internal measurement than is possible with the solid anvils of FIG. 1. Otherwise the structure is the same as before described.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. A precision internal taper micrometer comprising a pair of elongated anvils, each anvil having a generally flat surface and a partial conical surface, the flat surfaces facing each other, said anvils being arranged to present a single conical member when the flat surfaces thereof are in contact with each other, a pin transversely arranged on one anvil intermediate its ends and parallel to the plane of the fiat surfaces, the flat surfaces being removed from each other on an angle at one side of the pin, a member fixed to the other anvil receiving the pin and pivotally mounting the anvils for motion relative to each other so that the flat surfaces may approach or recede from each other, means comprising a direct read ing increment measuring device mounted on the other anvil and including a free-ended finger adjustable parallel to the axis of the closed conical member, said finger having a fiat face at its free end, a bar fixed to the one anvil in radial relation to the axis of the pin thereon, a cylindrical roll mounted on the bar in parallel relation to the pin but spaced therefrom, the fiat face of the finger engaging the surface of the roll transversely with respect thereto and moving it and the said one anvil relative to the other for accurate pivotal adjustment of the anvils relative to each other.

2. A precision internal taper micrometer comprising a pair of anvils, said anvils having partial conical surfaces thereon together forming a conical conformation when said anvil-s are in a certain position, said anvils also having facing flat surfaces, the anvils being pivotable relative to each other, a pivot pin on one anvil intermediate its ends and parallel to the plane of the flat surfaces, the flat surfaces being removed from each other on an angle at one side of the pin, a sine bar secured with respect to said pivot pin, said sine bar extengjiing outwardly from said one anvil in akdirectionr generally at right angles to the fiat surface thereof, a recess in the other anvil receiving a portion of the sine bar,..a cylindrical rollon said sine bar,..said sine bar having a free end; the roll being located at the free end of. the. sine bar; an inrernent measuring device including' a measuring screw finger adjustable parallel to the axis ofthe elosed conical member, said' finger contacting the. cylindrical roIl transversely thereof and deterinining the relative angularity of said anvils, and means mounting the measuring device on the other anvil in a position to present the screw finger to the roll.

References Cited by thelExaminer.

UNITED STATES PATENTS 402,876 5/1889 Welles 33-154 5 1,528,273 3/1925 Shwed 33178 2,502,051 3/1950 Kule-sar 33-178 X 3,085,345 4/1963 Pearson 33-4-74 ISAAC LISANN, Primary Examiner. LOUIS-R. PRINCE, Examiner. 

1. A PRECISION INTERNAL TAPER MICROMETER COMPRISING A PAIR OF ELONGATED ANVILS, EACH ANVIL HAVING A GENERALLY FLAT SURFACE AND A PARTIAL CONICAL SURFACE, THE FLAT SURFACES FACING EACH OTHER, SAID ANVILS BEING ARRANGED TO PRESENT A SINGLE CONICAL MEMBER WHEN THE FLAT SURFACES THEREOF ARE IN CONTACT WITH EACH OTHER, A PIN TRANSVERSELY ARRANGED ON ONE ANVIL INTERMEDIATE ITS ENDS AND PARALLEL TO THE PLANE OF THE FLAT SURFACES, THE FLAT SURFACES BEING REMOVED FROM EACH OTHER ON AN ANGLE AT ONE SIDE OF THE PIN, A MEMBER FIXED TO THE OTHER ANVIL RECEIVING THE PIN AND PIVOTALLY MOUNTING THE ANVILS FOR MOTION RELATIVE TO EACH OTHER SO THAT THE FLAT SURFACES MAY APPROACH OR RECEDE FROM EACH OTHER, MEANS COMPRISING A DIRECT READING INCREMENT MEASURING DEVICE MOUNTED ON THE OTHER 